Parametric Analysis and Optimization of an Elastocaloric Refrigeration Cycle
Abstract
Elastocaloric heating/cooling takes advantage of the structural changes in shape memory alloys (SMAs) that release and absorb heat when a strain is applied over a transition temperature. Heating/cooling cycles that use SMAs offer a potential solution to issues associated with the use of ozone-depleting refrigerants found in common heat pump/refrigeration cycles. Several recent works have found that the Coefficient of Performance (COP) for elastocaloric cycles is comparable to those achieved with standard HVAC systems of the same scale, which exhibit COPs of 3 on average. Conversely, SMA wires in lab settings have shown to achieve COPs as high as 3.5, and with sufficient optimization are expected to achieve COPs greater than 10. This study will be a continuation of the work performed by Sharar et al. (Army Research Lab), which established a first-of-its-kind solid-state continuous flow loop using nitinol (NiTi) wire. In this work, we explore the parametric space for optimization of Sharar's cycle using COMSOL Multiphysics (v. 5.5) to model the behavior of NiTi (an SMA) as strain is applied and released around a bend, where heat absorption and release occurs. We perform a parametric study that varies the wire radius, disk radius, its rotational speed, and its contact area with the primary heat sink to subsequently optimize its performance and to identify the parameters that will maximize COP, endothermic temperature change, and cooling power.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 12, 2021
- Accession Number
- AD1149677
Entities
People
- Sarah M. Nguyen
Organizations
- United States Naval Academy